Kraft Heinz shares traded at an all time low Friday after a dismal fourth quarter, coupled with an SEC notice and a grim 2019 outlook, lopped more than $15 billion in market value value from the packaged food group.

Kraft Heinz (KHC - Get Report) Kraft Heinz shares traded at an all time low Friday after a dismal fourth quarter, coupled with an SEC notice and a grim 2019 outlook, lopped more than $15 billion in market value value from the packaged food group.

Kraft Heinz said Thursday that it expects to "take a step backwards" this year after writing down the value of some of its key brands, including Kraft and Oscar Mayer, by as much as $15.4 billion. The group, which is one of Warren Buffett's key investments, sees 2019 earnings in the region of $6.3 billion to $6.5 billion, down 8.24% from last year at the higher end and well shy of the Street consensus forecast of $7.5 billion. The company also slashed its dividend to 40 cents per share after adjusted fourth quarter earnings came in 10 cents shy of the consensus forecast at 84 cents per share.

"While we expect to take a step backwards in 2019, we remain confident in delivering consistent profit growth from 2020 onwards, driven by fully leveraging our advantage brands, cost structures and capabilities," CFO David Knopf told investors on a conference call late Thursday.

Kraft Heinz shares were marked 27% lower at the start of trading Friday and changing hands at $35.20 each, an all-time low that would also take more than $3.4 billion from the value of Buffett's holding through his Berkshire Hathaway (BRK.A - Get Report) investment group.

Buffett has a 7.66% stake in Kraft Heinz, according to Berkshire's most recent SEC filing, with a cost basis of around $30 a share based on his original investment in the combined group, alongside private equity investors 3G Capital, in 2015.

Kraft Heinz has seen a steady decline in market share for its key brands, thanks in part to shifting consumer habits towards healthier options and competition from private label alternatives. It brought forward two years of investment plans into 2018, spending around $300 million in order to drive growth and develop its product pipeline, but fourth quarter net sales still fell shy of analysts forecasts and rose only 0.7% from last year to $6.9 billion.

"Where we fell short in 2018 was operations. Specifically, our entire EBITDA miss was driven by net savings versus expectations within our United States supply chain," said CEO Bernardo Hees. "There is no question we are disappointed that profitability did not ramp up with consumption gains as anticipated. We are overly optimistic on delivering savings that did not materialize by year-end."

"For that, we take full responsibility. And we have taken steps to ensure this does not happen again by touching planning process, procedures and organization structure," Hees added.

Kraft also said it had received a subpoena in October "associated with an investigation into" its accounting policies, procedures and internal controls related to its "procurement function."

This includes "agreements, side agreements, and changes or modifications to its agreements with its vendors," the company said. "Following this initial SEC document request, the Company together with external counsel launched an investigation into the procurement area."

"We continue to cooperate fully with the SEC and at this time the Company does not expect matters subject to the investigation to be material. For context, this $25 million increase to costs of products sold compares an annual procurement spend of over $11 billion annually for the total company," Kraft Heinz spokesman Michael Mullen told TheStreet in an email.